CVE-2018-16558
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability has been identified in SIMATIC S7-1500 CPU (All versions >= V2.0 and < V2.5), SIMATIC S7-1500 CPU (All versions <= V1.8.5). Specially crafted network packets sent to port 80/tcp or 443/tcp could allow an unauthenticated remote attacker to cause a Denial-of-Service condition of the device. The security vulnerability could be exploited by an attacker with network access to the affected systems on port 80/tcp or 443/tcp. Successful exploitation requires no system privileges and no user interaction. An attacker could use the vulnerability to compromise availability of the device. At the time of advisory publication no public exploitation of this security vulnerability was known.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA denial-of-service vulnerability exists in Siemens SIMATIC S7-1500 CPU devices where specially crafted network packets sent to HTTP (80/tcp) or HTTPS (443/tcp) ports can cause the device to become unavailable. The vulnerability can be exploited by an unauthenticated remote attacker with network access, requiring no privileges or user interaction.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 1.8.5>= 2.0, < 2.5CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the device modelAccess the device via TIA Portal or check the physical device labeling to confirm it is a Siemens SIMATIC S7-1500 CPU. The device model and article number are typically visible on the front panel or in the device configuration within the TIA Portal project.Affected if The device is a SIMATIC S7-1500 CPU.
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Determine the firmware versionConnect to the device using TIA Portal, navigate to the device properties, and check the firmware version field under 'General' > 'Device information'. Alternatively, access the device web server if enabled and check the firmware version displayed on the landing page.Affected if The firmware version is <= 1.8.5 or >= 2.0 and < 2.5.
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Verify if HTTP or HTTPS web services are enabledCheck the device configuration in TIA Portal under 'Web server' settings in the CPU properties. Confirm whether the built-in web server is activated and note whether HTTP, HTTPS, or both are enabled.Affected if The web server is enabled with HTTP on port 80/tcp or HTTPS on port 443/tcp.
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Check network exposure of web service portsScan the network to determine if ports 80/tcp and 443/tcp on the S7-1500 device are reachable from untrusted network segments. Use tools such as netstat, nmap, or the device's own network configuration to verify which IP addresses and interfaces these ports are bound to.Affected if Ports 80/tcp or 443/tcp are exposed to network segments accessible by unauthenticated remote attackers.
A user is affected if they have a SIMATIC S7-1500 CPU running firmware version <= 1.8.5 or >= 2.0 but < 2.5, with the web server enabled and ports 80/tcp or 443/tcp accessible to unauthenticated remote network attackers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data2.5
Upgrade SIMATIC S7-1500 CPU firmware to version V2.5 or later. For systems where immediate upgrade is not feasible, consider implementing network segmentation and firewalls to restrict unauthorized access to ports 80/tcp and 443/tcp.
- Consultation6.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-16558 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-16558 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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